1. Field of the Invention
This invention relates to a system and method for engraving using multiple engraving heads, and more particularly, to a multi-purpose engraver capable of performing engraving and exposing of workpieces.
2. Description of Related Art
The electro-mechanical engraving of a gravure cylinder involves rotating a cylinder while actuating an engraving head, or engraving heads having a diamond stylus carried on an oscillating shaft. The stylus cuts or engraves cells, lines of cells or tracks into the surface of the cylinder to produce an engraved cylinder for use in a printing process. The engraved cylinder is normally used in a web-type gravure printing press for printing paper, plastic, metallic film material, or other printed material.
In engravers for engraving cylinders used for printing publications, such as magazines or the like, the engraver may include multiple engraving heads wherein each engraving head includes a diamond stylus. By providing multiple heads, each head may be used to engrave different portions of the cylinder wherein each portion of the cylinder engraved by a respective head may, by way of example, correspond to a different page of the publication.
The movement of the styli for performing the engraving operation is precisely controlled to ensure that the engraved cells, or lines of cells or tracks formed by each engraving head are located at the desired positions on the cylinder. However, the initial positioning of the engraving heads relative to each has historically been very labor intensive wherein a skilled worker manually adjusts the position of each engraving head prior to an engraving operation.
Because of the manual intervention and because the styli of each engraver head wears differently, varying copper hardness in the surface of the cylinder, and differences in engraving response, characteristics of each engraving head and the like, it was difficult to use two or more engraving heads to engrave a continuous pattern. The cells or areas engraved by the different heads would not match-up, thereby creating an undesirable seam in the cylinder which may subsequently cause a visible printing defect.
Prior art etching systems gave the user the ability to laser expose resist on a surface of a workpiece. The workpiece would then be removed from the exposing device and subsequently etched (for example, chemically) in a manner conventionally known. Such exposing systems include the Digilas System and laser unit available from Schepers Druckformtechnik, Wxc3xcllener Strasse 60, 48691 Vreden, Germany; the Think(trademark) system offered by Think Laboratory Co., Ltd., 610-1 Umebayashi, Toyofuta, Kashiwa-shi, Chuba, Japan.
Prior art engraving systems provided means for engraving surfaces of workpieces using, for example, an electro-mechanical engraving head, a magnetostrictive engraving head, a piezo-electric engraving head, or a non-electro-mechanical engraving head, such as a laser engraving head. Prior art engraving systems included the Models 800 and 900 Systems available from Ohio Electronic Engravers, Inc., 4105 Executive Drive, Dayton, Ohio 45430; the LaserStar(trademark) and GravoStar(trademark) Systems available from MDC Max Dxc3xa4twyler AG, Flugpatz CH-3368, Bleienbach, Switzerland; as well as the K405 and K406 Systems available from Linotype Hell AG, Grenzstraxcex2e 2, 2300 Kiel 14, Federal Republic of Germany.
Thus, if a user desired to laser etch a workpiece and engrave either the same or a different workpiece, two separate systems had to be acquired because prior art systems lacked the ability to provide a single, multi-purpose system and method which enabled a user to both engrave and laser expose for etching one or more workpieces. This resulted in additional expense and required the user to have specially trained personnel.
Accordingly, there exists a need for a system and method for enabling multiple or a plurality of devices to be used in engraving and exposing, thereby facilitating engraving using multiple engraving techniques, including laser exposing, electro-mechanical engraving, laser engraving and the like.
In one aspect of this invention, this invention comprises an engraving system consisting of a plurality of engraving devices and a processor coupled to said plurality of engraving devices for energizing each of said plurality of engraving devices to engrave an intermeshing pattern.
In another aspect, this invention comprises a method for engraving an intermesh pattern on a cylinder in an engraver consisting of the steps of situating a plurality of engraving devices in operative relationship to said cylinder and engraving said intermesh pattern.
In still another aspect, this invention comprises a method for engraving a cylinder using a plurality of engraving heads consisting of the steps of situating a plurality of engraving heads in operative relationship with said cylinder and simultaneously energizing the plurality of engraving heads to engrave a blended pattern on the cylinder.
In yet another aspect an engraver comprises an engraving bed comprising a headstock and a tailstock adjustably mounted thereon, the headstock and tailstock being capable of rotatably supporting a cylinder therebetween, a carriage slidably mounted on the engraving bed; a first engraving head slidably mounted on the carriage; a second engraving head slidably mounted on the carriage; the first and second engraving heads having a circumferential offset therebetween; and, a first and second engraving head driver for energizing each of the first and second engraving heads, respectively, to engrave at least one pattern on the cylinder wherein the at least one pattern comprises tracks of engraved areas which were engraved by the first and second engraving heads.
In still another aspect, a method of engraving a pattern comprised of a plurality of tracks of engraved areas, comprises the steps of engraving at least one of the plurality of tracks with a first head, and engraving another of the plurality of tracks with a second head.
Therefore, it is an object of the present invention to provide a system and method for engraving a blended or intermeshed pattern using a plurality of engraving heads.
It is a further object of the invention to provide a system and method for engraving a continuous pattern of engraved areas engraved from a plurality of engraving heads.
It is yet another object of the invention to provide a system and method for imaging engraved areas which were engraved by the plurality of engraving heads in order to facilitate blending or intermeshing the engraved areas to provide a continuous engraved pattern.
Still another object of the invention, is to provide a single, multi-purpose system and method for engraving a workpiece using multiple engraving techniques.
Another object of the invention is to provide a single method and apparatus which enables exposing a resist on a workpiece for facilitating etching the workpiece and also provides an engraving device or head for engraving either the same workpiece or a second workpiece.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims.